A cross-layer approach to heterogeneity and reliability

As modern hardware becomes increasingly complex, it becomes more difficult to create efficient software for common computing workloads. One way to manage this complexity is to employ holistic solutions that consider multiple layers of hardware and software in conjunction, allowing software to adapt and react to changing conditions at run time. This paper focuses on lightweight modifications to commodity hardware that enable virtual execution environments to help solve problems in the areas of power, reliability, security, and performance. We present our experimental simulation framework, which enables us to explore the design space of hardware/software collaboration, and we demonstrate its ability to produce simplified, reactive solutions to two emerging computing problems. First, we improve heterogeneous process migration with hardware feedback, and second, we use hardware information to respond to voltage emergencies (di/dt) in software. These symbiotic design approaches illustrate the simple nature yet significant potential of cross-layer, reactive solutions.